... measuring function High accuracy true RMS Auto range, CE RS-232 interface VC8145 4 7/8 bench top digital multimeter DMM ... frequency,1%-99% Duty cycle,1800 pcs wave output;6,Single analyzed:(AC+DC) measuring synchronous,(AC+Hz) measuring synchronous,(DC ... Set upper limit,lower limit area measuring;17,photoelectricity insulation RS-232 computer interface;18,Timing measuring function;19,AC measuring adopt ...